Secondary reaction quench device and method of use

ABSTRACT

In this disclosure, a reactor system is described. The reaction system comprises (a) a reaction vessel having an inner wall, wherein said reaction vessel is configured to receive reactants and export products and byproducts; (b) a primary quench device (PQD) configured to receive a coolant and disperse said coolant into said reaction vessel; and (c) a secondary quench device (SQD) configured to receive a coolant and disperse said coolant into said reaction vessel; wherein said PQD comprises an array of spray nozzles fixed on the inner wall of said reaction vessel at a first axial position; and wherein said SQD comprises (1) an axially movable pipe having a coolant entry end and a nozzle end, wherein said pipe is configured to be removably fixed inside said reaction vessel; and (2) a spray nozzle that is fluidly connected to said pipe at its nozzle end via a fluid tight seal connection.

BACKGROUND

1. Technical Field of the Invention

This invention relates generally to the removal of carbon deposits invarious reactors. More specifically, this invention relates to anapparatus and a method for carbon removal (or carbon ablation), which isdeposited on the inner wall surfaces of reactors wherein thermalreactions take place.

2. Background of the Invention

Carbon deposits are commonly seen in reactors, especially thoseutilizing hydrocarbons or fuels to generate thermal energy. For example,when a stream of incompletely burned atomized fuel droplets reaches thewall of a combustor in a gas turbine engine, a localized reducingatmosphere is created. This enables carbon deposits to form on thecombustor wall. Periodic breaking off of pieces of these carbon depositscan result in significant erosion damage to the combustor in the gasturbine engine.

Another case is the production of acetylene, wherein natural gas isreacted at high temperatures to produce acetylene. These hightemperatures can be produced through the reaction of a fuel, such assyngas and oxidant such as oxygen. The production of acetylene, when inhigh enough concentration can lead to formation of carbon-containingsolids in the thermal reactor in the section downstream of thehydrocarbon gas inlet. The carbon-containing solids can accumulate onthe internal walls of the thermal reactor and impede flow through thereactor, resulting in increased differential pressure and/or spacevelocity. In some cases wherein the reacting gases pass through arestriction in the reactor, accumulation of carbon deposits in thisregion can impede the reaction or even stop the reaction because no flowis allowed to pass through.

Some reactors are equipped with carbon deposit removal apparatus. Butwhen the reactor operates at temperatures above which the materials ofthe removal apparatus are subject to mechanical or structuraldegradation, the apparatus cannot remain in the reaction zone of thereactor.

U.S. Pat. No. 4,243,633 discloses a closed reactor for the thermalcracking of heavy oils, having an internally mounted, rotatableinjection pipe. The injection pipe is adapted to spurt preheated rawmaterial under pressure against the inner wall surfaces of the reactorwhile rotating to remove carbon which has deposited on the reactor wallsduring the previous cracking operation. The injection pipe is insertedinto the reactor through a top opening in the reactor. The injectionpipe has two axially extended portions offset from one another, one ofwhich is located on the axis of the reactor and the other extends alongan interior wall surface of the reactor at a closely spaced distancefrom the wall surface. The injection pipe is provided with a multitudeof spouting jets longitudinally spaced along its length, each of thespouting jets is formed in the wall of said injection pipe at an angleof 25° to 90° with respect to the longitudinal axis of the injectionpipe.

U.S. Pat. No. 4,224,108 discloses a carbon removal apparatus that issuitable for use on a reaction vessel for the thermal cracking of heavypetroleum oils. This apparatus essentially includes a rotatable maininjection pipe to be disposed in the reaction vessel and has a multitudeof jet nozzles along its length, and a second or auxiliary injectionpipe positioned in the proximity of the main injection pipe to inject ascrubbing liquid over the outer peripheral walls of the main injectionpipe to prevent deposition of carbon. The main and auxiliary injectionpipes are both supplied with heavy petroleum oil to remove the carbondeposition from the reactor wall by the heavy petroleum oil jets fromthe main injection pipe while wetting the exterior of the main pipe withthe heavy petroleum oil injected by the auxiliary injection pipe.

U.S. Pat. No. 4,127,473 discloses a method for the batch thermalcracking of heavy oils, such as steam blowing for production of binderpitch. The method employs a reactor having a rotary injection pipe whichis rotatable within the reactor. Upon completion of the thermal crackingand withdrawal of the reaction product, the injection pipe ejectspreheated raw material under pressure against the interior wall surfacesof the reactor while in rotation to remove carbon which has deposited onthe reactor walls during the previous cracking operation.

U.S. Pat. No. 4,917,787 utilizes a reactor with an insulator. Insulatorsare physically weak materials compared to metals and are subject toablation, erosion, cracking and other physically degenerative mechanismswhen exposed to flowing gases, flowing gases that contain solids, liquidsprays, liquid sprays that contain solids, and other flowing media. Inaddition, insulators generally have porous surfaces compared to metalsonto which carbon deposits can attach and intrude into, making removalof said carbon deposits difficult or impossible without abrading orotherwise damaging the insulating surface and insulator integrity.

U.S. Pat. Nos. 3,557,241 and 3,365,387 disclose the introduction ofsufficient steam and/or water to at least one tube of the crackingfurnace while simultaneously reducing the hydrocarbon feed to that tube.The tube is then put back into service. The treatment of the tube iseffected at temperatures ranging from as low as 370° C. (700° F.) toabout 1100° C. (2000° F.). Such heat is supplied by external firing ofthe reactor tubes. Both Patents utilize a separate and distinct feedline for introducing steam and/or water for the on-stream carbon removalprocedure. These lines are controlled by a valve which is put intoservice on only those occasions when the individual tube in questionbeing subjected to carbon removal is undergoing such a cleaningoperation.

U.S. Pat. No. 3,920,537 deals with the carbon deposition evolving fromhydrocarbon cracking operations by “periodically contacting the carbondeposit with a jet of relatively cold, high-pressure water.” The Patentdescribes jetting the high-pressure cold water against the carbondeposit in an amount sufficient to thermally shock and break up thecarbon deposit, typically at a pressure in excess of about 5000 poundsper square inch. This type of carbon removal technique, however, is onlyparticularly useful where the carbon deposition occurs on surfaceshaving temperatures of approximately 370° C. (700° F.) to 538° C.(1,000° F.).

U.S. Pat. No. 4,203,778 effects carbon removal of furnace tubes by theuse of a turbulent stream of impact resistant, non-angular, non-abrasiveparticles entrained in a gas stream. The particles are entrained at aconcentration of 0.1 to 1.0 pound per pound of gas and the gas isintroduced into the inlet end of the furnace tubes at a gas flow ratecorresponding to an inlet velocity of 14,000 to 20,000 feet per minute.

Generally speaking, the prior art carbon removal procedures in thehydrocarbon cracking field, operate under certain process constraints.The prior art utilizes carbon removal procedures wherein the reactorsare made of metal. These processes are operated at reaction temperaturesnot exceeding about 1100° C. Because the reactors are made of metal, theheat for the carbon removal reactors is transferred through the walls.They usually require taking the reaction train equipment out of serviceand specially treating that equipment so as to reduce or eliminate thecoking problem. Furthermore, in most cases, these processes require thedismantling of equipment or the addition of equipment in order to effectcarbon removal. Such procedures are exceedingly time consuming, and addmaterially to the cost of the operation of the hydrocarbon crackingapparatus.

U.S. Pat. No. 4,849,025 uses an oxidant to oxidize the carbon and uses aliquid to take carbon away. Using an oxidant in this manner is adeparture from normal operating conditions under which the reaction ismeant to proceed. Changing the contents or stoichiometry in the reactorreduces conversion to the desired product and often the product is notcollected during this non-production stage. Also, changing operatingconditions of the reaction results in non-normal control states; thusnon-normal function required for process control devices such as controlvalves, flow meters, temperature indicators, pressure indicators andsimilar devices, complicates process control and the return to normaloperating conditions.

A mechanical apparatus to physically dislodge or scrub carbon particleshas been employed in some reactors. U.S. Pat. No. 4,196,050 (1980) ofTakahashi et al. describes a rotatable injection pipe for introductionof a scrubbing liquid with means for reciprocating motion.

U.S. Pat. No. 4,673,442 uses a physically reaming device to remove a bedof carbon from vessels used to produce carbon. Use of physical devicesto remove carbon deposits imparts shear and normal stress to the carbonthat are imparted to the reaction vessel which can damage or weaken thevessel, reducing its useful life. In addition, such devices can directlydeform, crack, or otherwise damage the surface when the device directlyimpacts the reactor vessel surface.

U.S. Pat. No. 4,626,320 utilizes hydro-blast drilling to removepetroleum carbon from delayed coking drums. Use of hydroblast drillingis disadvantageous because of the damage that very-high-velocity spraycan have on reactor internals and components.

U.S. Pat. No. 4,297,147 utilizes abrasive particles added to gas at highgas velocity for carbon removal. Use of abrasive particles leads toerosion of metal surfaces and reduces the useful lifetime of reactionvessels due to the scoring action that abrasive particles have at highvelocities. Also, high velocity particles tend to cause greater damageat bends, angles, corners and other direct or glancing impact locations.

Several methods for internal cleaning or carbon removal of hydrocarbonfurnace tubes are currently employed, the most common of which aremechanical cleaning (commonly known as turbining), hydroblasting, andstream-air carbon removal.

Turbining essentially consists of cutting or reaming the carbon depositsfrom the tube wall by passing a cutting head through each straightsection. This method requires that the furnace be disassembled to theextent that the inlet and outlet of each individual straight section oftube is exposed to allow entry of the cutting head. For those furnacesof welded return bend design this means that return bends must beinitially cut off and welded back in place after cleaning. Commercialsandblasting is usually employed to clean the return bends. This methodhas several major drawbacks, including: (1) that it results insubstantial downtime; (2) it is labor intensive; (3) it results insubstantial tube wall wear and subsequent premature tube failure as aresult of improper alignment of cutting head and furnace tube; and (4)it causes severe erosion of return bends.

The second technique, known as hydroblasting, is similar to turbiningexcept that, instead of the cutting tool, a hydraulic device is insertedinto each tube. The device produces high pressure water jets directednormal to the tube wall which dislodge the deposit by impact. Again,this method results in substantial downtime and is labor intensive forthe same reasons mentioned above. Furthermore, the high pressure watertends to dissolve sulfur initially deposited on the tube wall andresults in possible sulfuric acid corrosion of the tubes in addition tocreating a significant waste disposal problem.

Both of the above processes require that the furnace be cooled to nearatmospheric temperature. Not only does this result in significantadditional downtime, but in certain furnaces the cool down processitself can result in destruction of the furnace tubes. It is notuncommon during cool down for a furnace tube to fracture longitudinallyas a result of differential thermal contraction. The heavy inner layerof carbon has a significantly lower thermal expansion coefficientcompared to typical tubing material and can result in circumferentialthermal stresses in the tube wall in excess of its ultimate tensilestrength.

Probably the most common method of carbon removal furnace tubes is byinjecting metered amounts of steam and air into the tubes with thefurnace fired. The solid carbon is thus removed by a highly exothermicreaction between the solid carbon and air which generates a gas-solidstream of carbon particulate, CO, CO₂, SO₂ and NO_(x). The stream isused to cool the products of reaction. Process steps include: (1)removing the furnace from hydrocarbon service; (2) connecting carbonremoval lines to the furnace; and (3) introducing steam and air toinduce controlled burn out. Though furnace downtime is considerably lessthan for the above two processes, this steam-air process can result inserious and costly furnace damage. During the process, the tube skintemperature must be maintained within very narrow limits so as to bothsustain the temperature required to support the reaction and yet limitthe reaction temperature below the tube melting point. This highlyexothermic reaction frequently results in ruptured tubes and fittingsand hence costly downtime. In addition, the high temperature reaction ofoxygen can leave an oxide layer on the inner tube wall which willinhibit heat transfer. Mechanical cleaning or polishing must be used toremove the deposits subsequent to steam-air carbon removal operations.Finally, a further disadvantage of this process is that the effluentgases are highly toxic and thus create serious environmental problems,if not properly handled.

Therefore, there is continuing need and interest to develop apparatusand methods for removal of carbon deposits in various reactors.

SUMMARY

In an embodiment, a reactor system is disclosed. The reaction systemcomprises (a) a reaction vessel having an inner wall, wherein saidreaction vessel is configured to receive reactants and export productsand byproducts; (b) a primary quench device (PQD) configured to receivea coolant and disperse said coolant into said reaction vessel; and (c) asecondary quench device (SQD) configured to receive a coolant anddisperse said coolant into said reaction vessel; wherein said PQDcomprises an array of spray nozzles fixed on the inner wall of saidreaction vessel at a first axial position; and wherein said SQDcomprises (1) an axially movable pipe having a coolant entry end and anozzle end, wherein said pipe is configured to be removably fixed insidesaid reaction vessel; and (2) a spray nozzle that is fluidly connectedto said pipe at its nozzle end via a fluid tight seal connection.

In some embodiments, the spray nozzle of the SQD of the reactor systemis able to move upstream and downstream in the reaction vessel withrespect to the first axial position of the PQD. In some embodiments, thespray nozzle of the SQD of the reactor system is configured to dispersethe coolant onto the inner wall of the reaction vessel in the upstreamdirection at a spray angle of from 0° (radial direction) to 90° (axialdirection). In some embodiments, the spray nozzle of the SQD of thereactor system is configured to disperse the coolant onto the inner wallof the reaction vessel in the upstream direction at a spray angle offrom 0° to 70°.

In some embodiments, the reactor system further comprises an aligningmeans and a stabilizing means, both of which are configured to regulatethe movement of the axially movable pipe of the SQD. In someembodiments, the reactor system further comprises a separation systemconfigured to receive the byproducts from the reaction vessel. In someembodiments, the reactor system further comprises a cooling system.

In another embodiment, a method to remove carbon deposits is described.The method comprises (a) providing a reaction vessel having an innerwall, wherein said reaction vessel is configured to receive reactantsand export products and byproducts; (b) reacting said reactants to formsaid products and byproducts, wherein said byproducts comprise carbon,at least a portion of which becomes deposited on the inner wall of saidreaction vessel; (c) providing a primary quench device (PQD) configuredto receive a fluid and disperse said fluid into said reaction vessel,wherein said PQD comprises an array of spray nozzles fixed on the innerwall of said reaction vessel at a first axial position; (d) providing asecondary quench device (SQD) configured to receive a fluid and dispersesaid fluid into said reaction vessel, wherein said SQD comprises (1) anaxially movable pipe having a coolant entry end and a nozzle end,wherein said pipe is configured to be removably fixed inside saidreaction vessel; and (2) a spray nozzle that is fluidly connected tosaid pipe at its nozzle end via a fluid tight seal connection; (e)introducing a first coolant to the array of nozzles of said PQD at afirst flow rate and dispersing said first coolant through said array ofnozzles of the PQD to quench the reaction of said reactants in saidreaction vessel; (f) introducing a second coolant to the pipe of saidSQD at a second flow rate; and (g) dispersing the second coolant throughthe spray nozzle of said SQD onto the inner wall of said reaction vesselin the upstream direction to remove carbon deposits or to quench thereaction of said reactants or to accomplish both.

In some embodiments, steps (f) and (g) take place while the axiallymovable pipe of the SQD is moving inside the reaction vessel. In someembodiments, steps (f) and (g) take place while step (b) is taking placein the reaction vessel. In some embodiments, step (f) takes place at asufficient second flow rate before the axially movable pipe movesupstream in the reaction vessel beyond the first axial position of thePQD.

In some embodiments, the first flow rate is regulated to maintain thetemperature of the mixture of reactants in a desired range. In someembodiments, the movement of the movable pipe of the SQD, the first andsecond flow rates are regulated to maintain the temperature of themixture of reactants in desired ranges. In some embodiments, the firstcoolant and the second coolant are the same or different. In someembodiments, the first coolant or the second coolant is selected fromthe group consisting of water, oil, an inorganic solvent, an organicsolvent, a solvent derived from hydrocarbons, and combinations thereof.

In some embodiments, the duration for steps (f) and (g) to be inoperation is more than 10% of the duration for step (e) to be inoperation. In some embodiments, the duration for steps (f) and (g) to bein operation is between 0% and 100% of the duration for step (e) to bein operation. In some embodiments, the duration for steps (f) and (g) tobe in operation is between 50% and 100% of the duration for step (e) tobe in operation.

In some embodiments, the duration for steps (f) and (g) to be inoperation is less than 50% of the duration that step (b) is taking placein the reaction vessel. In some embodiments, the duration for steps (f)and (g) to be in operation is less than 10% of the duration that step(b) is taking place in the reaction vessel. In some embodiments, theduration for steps (f) and (g) to be in operation is between 0.1% and 1%of the duration that step (b) is taking place in the reaction vessel.

In some embodiments, the method to remove carbon deposits furthercomprises (h) collecting coolant with removed carbon deposits containedtherein from said reaction vessel; (i) separating said coolant from saidremoved carbon deposits; (j) cooling the separated coolant to a desiredtemperature range; and (k) recycling the cooled coolant to be reused instep (e) or step (f) or both. In embodiments, separating in step (i)comprises centrifugation and filtration.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the invention that follows may be better understood.Additional features and advantages of the invention will be describedhereinafter that form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiments disclosed may be readily utilized as a basisfor modifying or designing other structures for carrying out the samepurposes of the present invention. It should also be realized by thoseskilled in the art that such equivalent constructions do not depart fromthe spirit and scope of the invention as set forth in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more detailed description of the preferred embodiments of thepresent invention, reference will now be made to the accompanyingdrawings.

FIG. 1 schematically illustrates a thermal reactor with a primary quenchdevice and a secondary quench device for carbon deposit removal inaccordance with an embodiment of this disclosure.

FIG. 2 schematically illustrates a thermal reactor with a primary quenchdevice and a secondary quench device for carbon deposit removal inaccordance with another embodiment of this disclosure.

FIG. 3 schematically illustrates a thermal reactor with a primary quenchdevice and a secondary quench device for carbon deposit removal inaccordance with yet another embodiment of this disclosure.

DETAILED DESCRIPTION

Herein will be described in detail specific preferred embodiments of thepresent invention, with the understanding that the present disclosure isto be considered an exemplification of the principles of the inventionand is not intended to limit the invention to that illustrated anddescribed herein. The present invention is susceptible to preferredembodiments of different forms or order and should not be interpreted tobe limited to the specifically expressed methods or apparatus containedherein.

Overview

In an embodiment, a secondary quench device (SQD) is provided for carbondeposit removal (CDR) for a reaction vessel. In embodiments, the SQD isremovably fixed/attached inside a reaction vessel. In an embodiment, amethod for CDR is described utilizing a SQD that is furnished to areaction vessel. In embodiments, CDR takes place while the reactionvessel is being operated under normal conditions. In embodiments, themethod of CDR prevents on-line SQD from being damaged even though thenormal operating conditions in the reaction/combustion zone of thereaction vessel are severe enough to cause such damage.

Reaction Vessels

In embodiments, reaction vessels include combustors, turbines, engines,rocket motors, furnaces, tubular reactors, kilns, ovens, and any othersuitable reaction vessel known to one skilled in the art. Generallyspeaking, any vessel that is utilized to generate thermal energy byburning fuels is contemplated in this disclosure. Suitable fuels includesyngas, hydrocarbons, alcohols, carbon dioxide, ammonia, particulatecarbon, and any chemical or compound that contains carbon element andgenerates thermal energy when combined with an oxidant, such as oxygen,air, chlorine, bromine, other element or compound that acts as anoxidizer relative to the fuel at conditions under which a reaction takesplace. This disclosure does not intend to differentiate these reactionvessels by their type, shape, size, material of make, method of use, oroperation conditions.

Reaction Zones

In embodiments, reaction vessels comprise one or more reaction zones orcombustion zones. In some embodiments, the reaction zones in a reactionvessel are separated by a physical structure, which includes aninsulator, a metal plate, a matrix, a bed, and any structure that isknown to one skilled in the art. In some embodiments, the reaction zonesin a reaction vessel are separated by a thermal barrier, whetherphysical or non-physical. For example, one reaction zone of a reactionvessel is operated at a first temperature; another reaction zone of thesame vessel is operated at a second temperature that is 100° C. belowthe first temperature. In some embodiments, the reaction zones in areaction vessel are defined by a landmark for ease of reference. Forexample, two reaction zones may be defined as one above an inlet forintroduction of a substance and the other below the inlet. In someembodiments, the reaction zones in a reaction vessel are defined by anaction in operation for ease of reference. For example, two reactionzones may be defined as one in which introduction of a substance takesplace first and the other in which such introduction takes place secondin sequence. Generally speaking, a reaction zone may be defined byphysical separations, operating conditions, operational regimes, orsimply for ease of reference.

Primary Quench Device (PQD)

In an embodiment, a reaction vessel is equipped with a primary quenchdevice (PQD) which is in thermal communication with the reaction vesseleither directly or indirectly (e.g., through a physical thermalbarrier). In some cases, the PQD is a cooling jacket encasing at least aportion of the reaction vessel. In some cases, the PQD comprises anarray of spraying nozzles that introduce a coolant into the reactionvessel. In some cases, the PQD is integrated into the reaction vesselwall to cool down the temperature of the vessel wall. In someembodiments, the PQD is movable. In some embodiments, the PQD isimmovable. In some embodiments, the PQD is removably fixed inside thereaction vessel. In embodiments, the quenching capacity of the PQD isadjustable according to operational needs. The adjustment of the PQD isany suitable means known to one skilled in the art for each PQDconfiguration.

Secondary Quench Device (SQD)

In an embodiment, a reaction vessel is furnished with a secondary quenchdevice (SQD) which is in thermal communication with the reaction vesseleither directly or indirectly (e.g., through a physical thermalbarrier). In some cases, the SQD is a cooling jacket encasing at least aportion of the reaction vessel. In some cases, the SQD comprises anarray of spraying nozzles that introduce a coolant into the reactionvessel. In some cases, the SQD is integrated into the reaction vesselwall to cool down the temperature of the vessel wall. In someembodiments, the SQD is movable. In some embodiments, the SQD isimmovable. In some embodiments, the SQD is removably fixed inside thereaction vessel. In embodiments, the quenching capacity of the SQD isadjustable according to operational needs. The adjustment of the SQD isany suitable means known to one skilled in the art for each SQDconfiguration. In certain embodiments, SQD not only acts to removecarbon deposits but also provides a desired level of quenching/coolingfor the reaction mixture.

PQD and SQD are defined mainly for ease of reference and not meant to bedifferentiated by their quenching capacity, installation procedure,operation sequence, functional ability, or operational effects. As oneof ordinary skill in the art would understand, the concept of a SQD canbe easily expanded to include additional quench device; therefore theinclusion of any additional quench device for CDR is within the scope ofthis disclosure. In some embodiments, PQD, SQD, and any additionalquench device are coordinated to provide variable quenching effects forthe thermal reactor, which adjusts the composition of the productsobtained. In some embodiments, PQD, SQD, and any additional quenchdevice are coordinated to separate a thermal reactor into differentreaction zones, which are maintained at different reaction temperatures.In some cases, the temperatures of the reaction zones are maintained bythe adjustment of PQD, SQD, and any additional quench device.

Configuration 1

Referring now to FIG. 1, in an embodiment, a thermal reactor (100) isequipped with a PQD 170 and a SQD comprising a pipe 180 and a spraynozzle 190 for CDR. Thermal reactor 100 has a fuel inlet 115 for fuelstream 110 and an oxidant inlet 125 for oxidant stream 120. Gas stream130 for thermal treatment is introduced into reactor 100 via inlet 135.Coolant stream 140 is introduced to the PQD 170 via inlet 145. In anembodiment, PQD 170 is an array of spray nozzles fixed on the peripheryof the inner wall of thermal reactor 100. In embodiments, the positionsof inlets 115-145 are chosen according to the desired effects ofcombustion, thermal treatment, and quenching.

Thermal reactor has at least one outlet for products and byproductsformed during reactions to be extracted. The byproducts include carbon,at least a portion of which becomes deposited on the inner wall of thereactor. In FIG. 1, gaseous products are extracted via outlet 196 asstream 195; liquid products are extracted via outlet 194 as stream 193;and coolant with removed carbon deposits contained therein is extractedvia outlet 192 as stream 191.

In an embodiment, pipe 180 and spray nozzle 190 of the SQD are fluidlyconnected via a fluid tight seal connection. Coolant stream 160 isintroduced into pipe 180 and when the SQD is in operation, the coolantis dispersed into thermal reactor 100 via spray nozzle 190. In theembodiment shown in FIG. 1, pipe 180 together with nozzle 190 isdirected upward into thermal reactor 100 from the bottom of the reactor.In other embodiments, different configurations are contemplated as longas these configurations enable desired CDR function.

In some embodiments, the position of pipe 180 together with nozzle 190in the reactor is axially adjustable or movable, whichadjustment/movement may take place manually, mechanically, orautomatically. For example, position 150 shows a base position for theSQD and position 150′ shows an extended position for the SQD with dashedlines showing the pipe (180′) and the nozzle (190′). In someembodiments, axial adjustment/movement for the SQD takes place duringthe operation of the reactor. The axially adjustable pipe is furtherequipped with aligning and stabilizing mechanisms so that the axiallyadjustable pipe stays within the intended radial position of the thermalreactor. In some embodiments, the adjustment/movement of the SQD is donesmoothly in one step. In some embodiments, the adjustment/movement ofthe SQD is done smoothly in multiple steps. In some embodiments, theadjustment/movement of the SQD is done smoothly and sporadically indiscrete steps to satisfy specific CDR needs.

In embodiments, nozzle 190 is designed to allow the coolant to besprayed radially or at an angle between radial and axial directions ontothe inner wall of thermal reactor 100. The spray angle of nozzle 190 ofthe SQD is defined as 0° at the radial direction and 90° at the axialdirection. In some embodiments, the spray angle varies between 0°-90° inthe upstream direction. In some embodiments, the spray angle variesbetween 0°-70° in the upstream direction. In some embodiments, the sprayangle varies between 0°-90° in the downstream direction. In someembodiments, the spray angle varies between 0°-70° in the downstreamdirection. In certain embodiments, the spray angle varies between 0°-90°in both the upstream and downstream directions. In embodiments, axialmovement of pipe 180 and spray action of nozzle 190 may take placesimultaneously so that coolant is sprayed onto the desired surfaces ofthe inner wall of the thermal reactor for CDR. Exterior to the reactor,pipe 180 is connected by a hose to a pressurized source of fluid coolant(not shown in FIG. 1) so that fluid coolant may be directed through theaxially adjustable pipe and the nozzle as needed.

Operation 1

Referring to FIG. 1, the oxidation reaction (combustion) between fuel(stream 110) and oxidant (stream 120) in thermal reactor 100 raises thetemperature of the mixture to a range of from about 2000° C. to about3500° C. When gas stream 130 (e.g., hydrocarbon-containing gases)encounters this hot mixture, pyrolysis takes place, forming gas productscomprising acetylene, ethylene, carbon monoxide, hydrogen, carbondioxide, water vapor, propadiene, methylacetylene, and smaller amountsof other hydrocarbons and organic molecules. This product gas mixturehas a temperature in the range of from about 1700° C. and to about 3000°C.

This product gas mixture is then quenched by PQD 170 using the coolant(stream 140) provided. Suitable coolants include water, oil, aninorganic solvent, an organic solvent, a solvent derived fromhydrocarbons, and combinations thereof. Any fluid that does not reactwith the products of the thermal reactor may be used as a coolant. Theproduct gas or gas-liquid mixture that passes through the PQD generallyhas a temperature in the range of from about 100° C. to about 1000° C.

In embodiments, SQD comprising pipe 180 and nozzle 190 is activated whenCDR is desired. SQD moves axially to allow the spray of coolant to comein contact with the carbon deposits on the inner wall of the reactor,removing some or all of the carbon deposits. Suitable coolants includewater, oil, an inorganic solvent, an organic solvent, a solvent derivedfrom hydrocarbons, and combinations thereof. Any fluid that does notreact with the products of the thermal reactor may be used as a coolant.Carbon deposits form mainly upstream of the PQD on the inner wall of thethermal reactor. The spray angle of nozzle 190 and movement of pipe 180are adjusted to target the carbon deposits in that specific area. Evenwhen the spray nozzle is below the PQD, the coolant spray is still ableto reach the inner wall of the reactor that is above the PQD.

In embodiments, the flow rate of coolant in the PQD is adjusted toprovide a desired level of cooling/quenching. In embodiments, the flowrate of coolant in the PQD is adjusted to maintain the temperature ofthe reaction mixture within a desired range. In embodiments, the flowrate of coolant in the SQD is adjusted to provide a desired level ofCDR. In some embodiments, when not in operation, SQD comprising pipe 180and nozzle 190 is fully below PQD 170 so that the SQD is protected frombeing damaged by the reaction mixture prior to being cooled by the PQD.The selection of material for constructing the SQD is thereforeaccording to the highest temperature that it will encounter in a thermalreactor and may have economic advantages. In some embodiments, SQDcomprising pipe 180 and nozzle 190 only moves above the PQD in thethermal reactor when coolant is flowing through the SQD at an adequateflow rate, wherein the construction material for the SQD is able towithstand the conditions of the reaction mixture; without thecirculating coolant, the construction material for the SQD cannotwithstand such conditions.

In some embodiments, when in operation, the SQD only moves above the PQDfor a limited time in the thermal reactor. In some embodiments, prior toactivating spray nozzle 190 for CDR, the coolant is circulated insidethe SQD, including the axially adjustable pipe and spray nozzle. Inembodiments, CDR utilizing the SQD is carried out when the thermalreactor is in operation. In embodiments, the operation of the SQD iscontinuous and/or semi-continuous. In embodiments, the SQD is manuallyor automatically operated. In some embodiments, the movement of the SQDis programmed. In some embodiments, the SQD is removably fixed insidethe reactor. In some cases, the SQD stays inside the reactor whether ornot it is in operation. In some cases, the SQD is fixed inside thereactor only when it is to be operated.

In some embodiments, the time that the SQD is in operation is less than50% of the time the thermal reactor is operated. In this disclosure, athermal reactor being operated means that reactions are taking place inthe reactor unless otherwise specified. In some embodiments, the timethat the SQD is in operation is less than 10% of the time the thermalreactor is operated. In some embodiments, the time that the SQD is inoperation is between 0.1% and 1% of the time the thermal reactor isoperated. In some embodiments, the time that the SQD is in operation isbetween 0% and 100% of the time the PQD is operated. In someembodiments, the time that the SQD is in operation is between 50% and100% of the time the PQD is operated. In some embodiments, the time thatthe SQD is in operation is more than 10% of the time the PQD isoperated. In some embodiments, the SQD is operated before an operationof the thermal reactor starts. In some embodiments, the SQD is operatedafter an operation of the thermal reactor ends.

Configuration 2

Referring now to FIG. 2, in an embodiment, a thermal reactor (200) isequipped with a PQD 270 and a SQD comprising a pipe 280 and a spraynozzle 290 for CDR. Thermal reactor 200 has reaction Zone 1 above thePQD 270 and reaction Zone 2 below the PQD 270 and above the SQD. Thermalreactor 200 has a fuel inlet 215 for fuel stream 210 and an oxidantinlet 225 for oxidant stream 220. Gas stream 230 for thermal treatmentis introduced into reactor 200 via inlet 235. Coolant stream 240 isintroduced to the PQD 270 via inlet 245. In an embodiment, PQD 270 is anarray of spray nozzles fixed on the periphery of the inner wall ofthermal reactor 200. In embodiments, the positions of inlets 215-245 arechosen according to the desired effects of combustion, thermaltreatment, and quenching.

Thermal reactor has at least one outlet for products and byproductsformed during reactions to be extracted. The byproducts include carbon,at least a portion of which becomes deposited on the inner wall of thereactor. In FIG. 2, gaseous products are extracted via outlet 296 asstream 295; liquid products are extracted via outlet 294 as stream 293;and coolant with removed carbon deposits contained therein is extractedvia outlet 292 as stream 291.

In an embodiment, pipe 280 and spray nozzle 290 of the SQD are fluidlyconnected via a fluid tight seal connection. Coolant stream 260 isintroduced into pipe 280 and when the SQD is in operation, the coolantis dispersed into thermal reactor 200 via spray nozzle 290. In theembodiment shown in FIG. 2, pipe 280 together with nozzle 290 isdirected upward into thermal reactor 200 from the bottom of the reactor.In other embodiments, different configurations are contemplated as longas these configurations enable desired CDR function.

In some embodiments, the position of pipe 280 together with nozzle 290in the reactor is axially adjustable or movable, whichadjustment/movement may take place manually, mechanically, orautomatically. Position 250 in FIG. 2 shows a possible position for theSQD comprising pipe 280 and spray nozzle 290. In some embodiments, axialadjustment/movement for the SQD takes place during the operation of thereactor. The axially adjustable pipe is further equipped with aligningand stabilizing mechanisms so that the axially adjustable pipe stayswithin the intended radial position of the thermal reactor. In someembodiments, the adjustment/movement of the SQD is done smoothly in onestep. In some embodiments, the adjustment/movement of the SQD is donesmoothly in multiple steps. In some embodiments, the adjustment/movementof the SQD is done smoothly and sporadically in discrete steps tosatisfy specific CDR needs.

In embodiments, nozzle 290 is designed to allow the coolant to besprayed radially or at an angle between radial and axial directions ontothe inner wall of thermal reactor 200. The spray angle of nozzle 190 ofthe SQD is defined as 0° at the radial direction and 90° at the axialdirection. In some embodiments, the spray angle varies between 0°-90° inthe upstream direction. In some embodiments, the spray angle variesbetween 0°-70° in the upstream direction. In some embodiments, the sprayangle varies between 0°-90° in the downstream direction. In someembodiments, the spray angle varies between 0°-70° in the downstreamdirection. In certain embodiments, the spray angle varies between 0°-90°in both the upstream and downstream directions. In embodiments, axialmovement of pipe 280 and spray action of nozzle 290 may take placesimultaneously so that coolant is sprayed onto the desired surfaces ofthe inner wall of the thermal reactor for CDR. Exterior to the reactor,pipe 280 is connected by a hose to a pressurized source of fluid coolant(not shown in FIG. 2) so that fluid coolant may be directed through theaxially adjustable pipe and the nozzle as needed.

Operation 2

Referring to FIG. 2, the oxidation reaction (combustion) between fuel(stream 210) and oxidant (stream 220) in thermal reactor 200 raises thetemperature of the mixture to a range of from about 2000° C. to 3500° C.When gas stream 230 (e.g., hydrocarbon-containing gases) encounters thishot mixture, pyrolysis takes place, forming gas products comprisingacetylene, ethylene, carbon monoxide, hydrogen, carbon dioxide, watervapor, propadiene, methylacetylene, and smaller amounts of otherhydrocarbons and organic molecules. This product gas mixture has atemperature in the range of from about 1700° C. and to about 3000° C.

This product gas mixture is then quenched by PQD 270 using the coolant(stream 240) provided. Suitable coolants include water, oil, aninorganic solvent, an organic solvent, a solvent derived fromhydrocarbons, and combinations thereof. Any fluid that does not reactwith the products of the thermal reactor may be used as a coolant. Theproduct gas or gas-liquid mixture that passes through the PQD generallyhas a temperature in the range of from about 100° C. to about 1000° C.

In embodiments, SQD comprising pipe 280 and nozzle 290 is activated whenCDR is desired. The spray of coolant comes in contact with the carbondeposits on the inner wall of the reactor, removing some or all of thecarbon deposits. Suitable coolants include water, oil, an inorganicsolvent, an organic solvent, a solvent derived from hydrocarbons, andcombinations thereof. Any fluid that does not react with the products ofthe thermal reactor may be used as a coolant. Carbon deposits formmainly upstream of the PQD on the inner wall of the thermal reactor. Thespray angle of nozzle 290 and movement of pipe 280 are adjusted totarget the carbon deposits in that specific area. In some embodiments,even when the spray nozzle is below the PQD, the coolant spray is stillable to reach the inner wall of the reactor that is above the PQD.

In embodiments, the flow rate of coolant in the PQD is adjusted toprovide a desired level of cooling/quenching. In embodiments, the flowrate of coolant in the PQD is adjusted to maintain the temperature ofthe reaction mixture within a desired range. For example, this desiredtemperature range is the temperature range for reaction Zone 1, which isa primary reaction zone. In embodiments, the flow rate of coolant in theSQD is adjusted to provide a desired level of CDR. In some embodiments,the SQD provides additional quenching/cooling to the reaction mixtureafter it is cooled by the PQD. In embodiments, the flow rate of coolantin the SQD is adjusted to maintain the temperature of the reactionmixture within a desired range. This desired temperature range is lowerthan the temperature of reaction Zone 1, which is a primary reactionzone; it may be any temperature between the maximum achievabletemperature and the temperature at which all reactions cease.

In some embodiments, the PQD and SQD are coordinated to provide variablequenching effects for the thermal reactor, which adjusts the compositionof the products obtained. For example, reaction Zone 1 (a primaryreaction zone) may be maintained at a first temperature range andreaction Zone 2 (a secondary reaction zone) may be maintained at asecond temperature range, wherein the second temperature range is lowerthan the first. As a result, different thermal reactions may take placein Zone 1 and Zone 2, rendering different reaction products. Thetemperature ranges at which Zone 1 and Zone 2 are maintained areaccording to the desired product compositions for each specificoperation. Variable operation parameters include type of coolant,temperature of coolant, flow rate of coolant for PQD or SQD or both,moving speed of SQD, moving pattern of SQD, spray duration, spraypattern, spray angle, and spray frequency.

In some embodiments, the SQD is maintained at a position axiallydownstream of the PQD. This has the advantage of protecting the SQD frombeing damaged by the high temperature of the reaction mixture prior tobeing cooled by the PQD. Also, the material for constructing the SQD isselected according to the highest temperature that it will encounter ina thermal reactor and may have economic advantages. In some embodiments,prior to activating spray nozzle 290 for CDR, the coolant is circulatedinside the SQD, including the axially adjustable pipe and spray nozzle.In embodiments, CDR utilizing the SQD is carried out when the thermalreactor is in operation. In embodiments, the operation of the SQD iscontinuous and/or semi-continuous. In embodiments, the SQD is manuallyor automatically operated. In some embodiments, the movement of the SQDis programmed. In some embodiments, the SQD is removably fixed insidethe reactor. In some cases, the SQD stays inside the reactor whether ornot it is in operation. In some cases, the SQD is fixed inside thereactor only when it is to be operated.

In some embodiments, the time that the SQD is in operation is less than50% of the time the thermal reactor is operated. In this disclosure, athermal reactor being operated means that reactions are taking place inthe reactor unless otherwise specified. In some embodiments, the timethat the SQD is in operation is less than 10% of the time the thermalreactor is operated. In some embodiments, the time that the SQD is inoperation is between 0.1% and 1% of the time the thermal reactor isoperated. In some embodiments, the time that the SQD is in operation isbetween 0% and 100% of the time the PQD is operated. In someembodiments, the time that the SQD is in operation is between 50% and100% of the time the PQD is operated. In some embodiments, the time thatthe SQD is in operation is more than 10% of the time the PQD isoperated. In some embodiments, the SQD is operated before an operationof the thermal reactor starts. In some embodiments, the SQD is operatedafter an operation of the thermal reactor ends.

Configuration 3

Referring to FIG. 3, in an embodiment, a thermal reactor (300) isequipped with a PQD 370 and a SQD comprising a pipe 380 and a spraynozzle 390 for CDR. Thermal reactor 300 has reaction Zone 1 above theSQD and reaction Zone 2 below the SQD and above the PQD. Thermal reactor300 has a fuel inlet 315 for fuel stream 310 and an oxidant inlet 325for oxidant stream 320. Gas stream 330 for thermal treatment isintroduced into reactor 300 via inlet 335. Coolant stream 340 isintroduced to the PQD 370 via inlet 345. In an embodiment, PQD 370 is anarray of spray nozzles fixed on the periphery of the inner wall ofthermal reactor 300. In embodiments, the positions of inlets 315-345 arechosen according to the desired effects of combustion, thermaltreatment, and quenching.

Thermal reactor has at least one outlet for products and byproductsformed during reactions to be extracted. The byproducts include carbon,at least a portion of which becomes deposited on the inner wall of thereactor. In FIG. 3, gaseous products are extracted via outlet 396 asstream 395; liquid products are extracted via outlet 394 as stream 393;and coolant with removed carbon deposits contained therein is extractedvia outlet 392 as stream 391.

In an embodiment, pipe 380 and spray nozzle 390 of the SQD are fluidlyconnected via a fluid tight seal connection. Coolant stream 360 isintroduced into pipe 380 and when the SQD is in operation, the coolantis dispersed into thermal reactor 300 via spray nozzle 390. In theembodiment shown in FIG. 3, pipe 380 together with nozzle 390 isdirected upward into thermal reactor 300 from the bottom of the reactor.In other embodiments, different configurations are contemplated as longas these configurations enable desired CDR function.

In some embodiments, the position of pipe 380 together with nozzle 390in the reactor is axially adjustable or movable, whichadjustment/movement may take place manually, mechanically, orautomatically. Position 350 in FIG. 3 shows a possible position for theSQD comprising pipe 380 and spray nozzle 390. In some embodiments, axialadjustment/movement for the SQD takes place during the operation of thereactor. The axially adjustable pipe is further equipped with aligningand stabilizing mechanisms so that the axially adjustable pipe stayswithin the intended radial position of the thermal reactor. In someembodiments, the adjustment/movement of the SQD is done smoothly in onestep. In some embodiments, the adjustment/movement of the SQD is donesmoothly in multiple steps. In some embodiments, the adjustment/movementof the SQD is done smoothly and sporadically in discrete steps tosatisfy specific CDR needs.

In embodiments, nozzle 390 is designed to allow the coolant to besprayed radially or at an angle between radial and axial directions ontothe inner wall of thermal reactor 300. The spray angle of nozzle 390 ofthe SQD is defined as 0° at the radial direction and 90° at the axialdirection. In some embodiments, the spray angle varies between 0°-90° inthe upstream direction. In some embodiments, the spray angle variesbetween 0°-70° in the upstream direction. In some embodiments, the sprayangle varies between 0°-90° in the downstream direction. In someembodiments, the spray angle varies between 0°-70° in the downstreamdirection. In certain embodiments, the spray angle varies between 0°-90°in both the upstream and downstream directions. In embodiments, axialmovement of pipe 380 and spray action of nozzle 390 take placesimultaneously so that coolant is sprayed onto the desired surfaces ofthe inner wall of the thermal reactor for CDR. Exterior to the reactor,pipe 380 is connected by a hose to a pressurized source of fluid coolant(not shown in FIG. 3) so that fluid coolant may be directed through theaxially adjustable pipe and the nozzle as needed.

Operation 3

In embodiments, SQD comprising pipe 380 and nozzle 390 is activated whenCDR is desired. The spray of coolant comes in contact with the carbondeposits on the inner wall of the reactor, removing some or all of thecarbon deposits. Suitable coolants include water, oil, an inorganicsolvent, an organic solvent, a solvent derived from hydrocarbons, andcombinations thereof. Any fluid that does not react with the products ofthe thermal reactor may be used as a coolant.

In some embodiments, the SQD is maintained at a position above the PQD.The gas products at a high temperature are initially cooled/quenched bythe SQD and further cooled/quenched by the PQD. SQD not only acts tocause CDR but also provides quenching for the reaction mixture. In someembodiments, the coolant flows through the SQD at an adequate flow rateso that the construction material for the SQD is able to withstand theconditions of the reaction mixture. In embodiments, the flow rate ofcoolant in the SQD is adjusted to maintain the temperature of thereaction mixture within a desired range. This desired temperature rangeis lower than the temperature of reaction Zone 1, which is a primaryreaction zone; it may be any temperature between the maximum achievabletemperature and the temperature at which all reactions cease.

In some embodiments, the PQD and SQD are coordinated to provide variablequenching effects for the thermal reactor, which adjusts the compositionof the products obtained. For example, reaction Zone 1 (a primaryreaction zone) may be maintained at a first temperature range andreaction Zone 2 (a secondary reaction zone) may be maintained at asecond temperature range, wherein the second temperature range is lowerthan the first. As a result, different thermal reactions may take placein Zone 1 and Zone 2, rendering different reaction products. Thetemperature ranges at which Zone 1 and Zone 2 are maintained areaccording to the desired product compositions for each specificoperation. Variable operation parameters include type of coolant,temperature of coolant, flow rate of coolant for PQD or SQD or both,moving speed of SQD, moving pattern of SQD, spray duration, spraypattern, spray angle, and spray frequency. In certain cases, when theSQD functions sufficiently, the PQD does not need to provide anycooling/quenching (no flow into inlet 345 or flow rate of stream 340being zero).

In some embodiments, prior to activating spray nozzle 390 for CDR andquenching, the coolant is circulated inside the SQD, including theaxially adjustable pipe and spray nozzle. In embodiments, CDR andquenching utilizing the SQD take place simultaneously when the thermalreactor is in operation. In embodiments, the operation of the SQD iscontinuous and/or semi-continuous. In embodiments, the SQD is manuallyor automatically operated. In some embodiments, the movement of the SQDis programmed. In some embodiments, the SQD is removably fixed insidethe reactor. In some cases, the SQD stays inside the reactor whether ornot it is in operation. In some cases, the SQD is fixed inside thereactor only when it is to be operated.

In some embodiments, the time that the SQD is in operation is less than50% of the time the thermal reactor is operated. In this disclosure, athermal reactor being operated means that reactions are taking place inthe reactor unless otherwise specified. In some embodiments, the timethat the SQD is in operation is less than 10% of the time the thermalreactor is operated. In some embodiments, the time that the SQD is inoperation is between 0.1% and 1% of the time the thermal reactor isoperated. In some embodiments, the time that the SQD is in operation isbetween 0% and 100% of the time the PQD is operated. In someembodiments, the time that the SQD is in operation is between 50% and100% of the time the PQD is operated. In some embodiments, the time thatthe SQD is in operation is more than 10% of the time the PQD isoperated. In some embodiments, the SQD is operated before an operationof the thermal reactor starts. In some embodiments, the SQD is operatedafter an operation of the thermal reactor ends.

Coolant Recycle

In embodiments, the coolant with removed carbon deposits is collectedand passed through a downstream separation means (such ascentrifugation, filtration) to separate the carbon deposits from thecoolant (not shown in FIGS. 1-3). In some embodiments, the separationsystem is operated at a pressure at which the coolant is a liquid. Insome embodiments, the coolant is further passed through a cooling systemto be recycled and reused in the PQD or SQD or both.

While the preferred embodiments of the invention have been shown anddescribed, modifications thereof can be made by one skilled in the artwithout departing from the spirit and teachings of the invention.Process criteria, equipment, and the like for any given implementationof the invention will be readily ascertainable to one of skill in theart based upon the disclosure herein. Use of the term “optionally” withrespect to any element of the invention is intended to mean that thesubject element is required, or alternatively, is not required. Bothalternatives are intended to be within the scope of the invention. Theembodiments described herein are exemplary only and are not intended tobe limiting. Many variations and modifications of the inventiondisclosed herein are possible and are within the scope of the invention.Accordingly, the scope of protection is not limited by the descriptionset out above, but is only limited by the claims which follow, thatscope including all equivalents of the subject matter of the claims.

The discussion of a reference in the Background is not an admission thatit is prior art to the present invention, especially any reference thatmay have a publication date after the priority date of this application.The disclosures of all patents, patent applications, and publicationscited herein are hereby incorporated herein by reference in theirentirety, to the extent that they provide exemplary, procedural, orother details supplementary to those set forth herein.

1. A reactor system comprising a reaction vessel having an inner wall,wherein said reaction vessel is configured to receive reactants andexport products and byproducts; a primary quench device (PQD) configuredto receive a coolant and disperse said coolant into said reactionvessel; and a secondary quench device (SQD) configured to receive acoolant and disperse said coolant into said reaction vessel; whereinsaid PQD comprises an array of spray nozzles fixed on the inner wall ofsaid reaction vessel at a first axial position; and wherein said SQDcomprises an axially movable pipe having a coolant entry end and anozzle end, wherein said pipe is configured to be removably fixed insidesaid reaction vessel; and a spray nozzle that is fluidly connected tosaid pipe at its nozzle end via a fluid tight seal connection.
 2. Thereactor system of claim 1, wherein the spray nozzle of said SQD is ableto move upstream and downstream in the reaction vessel with respect tothe first axial position of said PQD.
 3. The reactor system of claim 1,wherein the spray nozzle of said SQD is configured to disperse thecoolant onto the inner wall of said reaction vessel in the upstreamdirection at a spray angle of from 0° (radial direction) to 90° (axialdirection).
 4. The reactor system of claim 1, wherein the spray nozzleof said SQD is configured to disperse the coolant onto the inner wall ofsaid reaction vessel in the upstream direction at a spray angle of from0° to 70°.
 5. The reactor system of claim 1 further comprising analigning means and a stabilizing means, wherein said aligning means andstabilizing means are configured to regulate the movement of the axiallymovable pipe of said SQD.
 6. The reactor system of claim 1 furthercomprising a separation system configured to receive the byproducts fromsaid reaction vessel.
 7. The reactor system of claim 1 furthercomprising a cooling system.
 8. A method to remove carbon depositscomprising (a) providing a reaction vessel having an inner wall, whereinsaid reaction vessel is configured to receive reactants and exportproducts and byproducts; (b) reacting said reactants to form saidproducts and byproducts, wherein said byproducts comprise carbon, atleast a portion of which becomes deposited on the inner wall of saidreaction vessel; (c) providing a primary quench device (PQD) configuredto receive a fluid and disperse said fluid into said reaction vessel,wherein said PQD comprises an array of spray nozzles fixed on the innerwall of said reaction vessel at a first axial position; (d) providing asecondary quench device (SQD) configured to receive a fluid and dispersesaid fluid into said reaction vessel, wherein said SQD comprises anaxially movable pipe having a coolant entry end and a nozzle end,wherein said pipe is configured to be removably fixed inside saidreaction vessel; and a spray nozzle that is fluidly connected to saidpipe at its nozzle end via a fluid tight seal connection; (e)introducing a first coolant to the array of nozzles of said PQD at afirst flow rate and dispersing said first coolant through said array ofnozzles of said PQD to quench the reaction of said reactants in saidreaction vessel; (f) introducing a second coolant to the pipe of saidSQD at a second flow rate; and (g) dispersing the second coolant throughthe spray nozzle of said SQD onto the inner wall of said reaction vesselin the upstream direction to remove carbon deposits or to quench thereaction of said reactants or to accomplish both.
 9. The method of claim8, wherein steps (f) and (g) take place while the axially movable pipeof said SQD is moving inside the reaction vessel.
 10. The method ofclaim 8, wherein steps (f) and (g) take place while step (b) is takingplace in said reaction vessel.
 11. The method of claim 8, wherein step(f) takes place at a sufficient second flow rate before the axiallymovable pipe moves upstream in the reaction vessel beyond the firstaxial position of said PQD.
 12. The method of claim 8, wherein the firstflow rate is regulated to maintain the temperature of the mixture ofreactants in a desired range.
 13. The method of claim 8, wherein themovement of the movable pipe of said SQD, the first and second flowrates are regulated to maintain the temperature of the mixture ofreactants in desired ranges.
 14. The method of claim 8, wherein saidfirst coolant and said second coolant are the same or different.
 15. Themethod of claim 8, wherein said first coolant or said second coolant isselected from the group consisting of water, oil, an inorganic solvent,an organic solvent, a solvent derived from hydrocarbons, andcombinations thereof.
 16. The method of claim 8, wherein the durationfor steps (f) and (g) to be in operation is more than 10% of theduration for step (e) to be in operation.
 17. The method of claim 8,wherein the duration for steps (f) and (g) to be in operation is between0% and 100% of the duration for step (e) to be in operation.
 18. Themethod of claim 8, wherein the duration for steps (f) and (g) to be inoperation is less than 50% of the duration that step (b) is taking placein said reaction vessel.
 19. The method of claim 8, wherein the durationfor steps (f) and (g) to be in operation is less than 10% of theduration that step (b) is taking place in said reaction vessel.
 20. Themethod of claim 8, wherein the duration for steps (f) and (g) to be inoperation is between 0.1% and 1% of the duration that step (b) is takingplace in said reaction vessel.
 21. The method of claim 8 furthercomprising (h) collecting coolant with removed carbon deposits containedtherein from said reaction vessel; (i) separating said coolant from saidremoved carbon deposits; (j) cooling the separated coolant to a desiredtemperature range; and (k) recycling the cooled coolant to be reused instep (e) or step (f) or both.
 22. The method of claim 21, wherein saidseparating in step (i) comprises centrifugation and filtration.